Purpose: The relative darkness of the eyes and mouth compared to the surrounding skin has been suggested to be a unique aspect of faces as a class. The goal of these experiments was to determine whether the size of this luminance contrast plays a role in facial attractiveness. Besides providing insights regarding the determinants of facial aesthetics, this study also has implications for understanding how cosmetics enhance attractiveness. Method: Grayscale images of male and female faces were manipulated such that the contrast between the average luminance of the eyes and mouth and that of the rest of the face was increased, decreased, or left unchanged. Subjects rated the attractiveness of all three versions of each face on a Likert scale. Results: Images of male faces were judged more attractive with this kind of contrast reduced than with it increased. Images of female faces were judged more attractive with this contrast increased than with it decreased. Discussion: The manipulations had opposite effects on male and female faces. This suggests a possible explanation of the results based on the notion that changes that accentuate differences between male and female faces tend to enhance perceived attractiveness. Preliminary investigations with a collection of male and female faces suggest that female faces have greater luminance contrast between the eyes and mouths and the rest of the face than do male faces. Stimuli wherein this sex difference is accentuated may prove to be more attractive than the originals. Much of cosmetics serve to darken the eyes and lips of females, and their effectiveness may lie in accentuating this sex difference in contrast.